The invention relates to a belt retractor comprising a belt reel supported in a housing onto which belt reel webbing of a seat belt can be wound and comprising a damping means adapted to dampen the winding rotation of the belt reel in a defined end portion.
Several belt retractors for seat belts include a damping means for decelerating the retracting movement of the belt reel shortly before the seat belt is completely retracted onto the belt reel. When the retracting movement is not decelerated, due to the high retracting speed and the inertia the webbing-sensitive blocking mechanism of the belt retractor can react after complete retraction of the seat belt and block the belt reel so that extension of the seat belt is not possible. The blocking mechanism can only be released by rotating the belt reel in the retracting direction. Since, however, the seat belt is completely wound up, this is possible only by pulling the seat belt so strongly that a short piece of the seat belt can be taken off by the reel of film effect. When the seat belt is subsequently released, the belt reel can slightly return and the blocking mechanism can be released.
In order to prevent such undesired blocking, from DE 103 44 785 A1, for example, a belt retractor comprising a damping means adapted to be coupled to the belt reel via a planetary gearing is known. The planetary gearing includes a control disk having a toothed profile in a defined area of the outer periphery. With a defined number of revolutions of the belt reel the control disk is pivoted so that it is engaged in a gearwheel coupled to the damping means, whereby a force-fit connection is made between the belt reel and the damping means.
It is a drawback of this belt retractor, however, that the coupling takes place in a defined area only which is predefined by the control disk and the planetary gearing, respectively. Adaptation to a different length of the webbing is only possible by appropriately adapting the control disk and the planetary gearing, respectively.